com.ibm.icu.util.RangeValueIterator Maven / Gradle / Ivy
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
******************************************************************************
* Copyright (C) 1996-2016, International Business Machines Corporation and *
* others. All Rights Reserved. *
******************************************************************************
*/
package com.ibm.icu.util;
/**
* Interface for enabling iteration over sets of <int index, int value>,
* where index is the sorted integer index in ascending order and value, its
* associated integer value.
*
The result for each iteration is the consecutive range of
* <int index, int value> with the same value. Result is represented by
* <start, limit, value> where
*
* - start is the starting integer of the result range
*
- limit is 1 after the maximum integer that follows start, such that
* all integers between start and (limit - 1), inclusive, have the same
* associated integer value.
*
- value is the integer value that all integers from start to (limit - 1)
* share in common.
*
*
* Hence value(start) = value(start + 1) = .... = value(start + n) = .... =
* value(limit - 1). However value(start -1) != value(start) and
* value(limit) != value(start).
*
*
Most implementations will be created by factory methods, such as the
* character type iterator in UCharacter.getTypeIterator. See example below.
*
*
Example of use:
*
* RangeValueIterator iterator = UCharacter.getTypeIterator();
* RangeValueIterator.Element result = new RangeValueIterator.Element();
* while (iterator.next(result)) {
* System.out.println("Codepoint \\u" +
* Integer.toHexString(result.start) +
* " to codepoint \\u" +
* Integer.toHexString(result.limit - 1) +
* " has the character type " + result.value);
* }
*
* @author synwee
* @stable ICU 2.6
*/
public interface RangeValueIterator
{
// public inner class ---------------------------------------------
/**
* Return result wrapper for com.ibm.icu.util.RangeValueIterator.
* Stores the start and limit of the continous result range and the
* common value all integers between [start, limit - 1] has.
* @stable ICU 2.6
*/
public class Element
{
// public data member ---------------------------------------------
/**
* Starting integer of the continuous result range that has the same
* value
* @stable ICU 2.6
*/
public int start;
/**
* (End + 1) integer of continuous result range that has the same
* value
* @stable ICU 2.6
*/
public int limit;
/**
* Gets the common value of the continous result range
* @stable ICU 2.6
*/
public int value;
// public constructor --------------------------------------------
/**
* Empty default constructor to make javadoc happy
* @stable ICU 2.4
*/
public Element()
{
}
}
// public methods -------------------------------------------------
/**
* Returns the next maximal result range with a common value and returns
* true if we are not at the end of the iteration, false otherwise.
*
If this returns a false, the contents of elements will not
* be updated.
* @param element for storing the result range and value
* @return true if we are not at the end of the iteration, false otherwise.
* @see Element
* @stable ICU 2.6
*/
public boolean next(Element element);
/**
* Resets the iterator to the beginning of the iteration.
* @stable ICU 2.6
*/
public void reset();
}